Field of the Disclosure
The present disclosure relates to a liquid discharge head including a recording element substrate and an electric element mounted outside the recording element substrate.
Description of the Related Art
A typical liquid discharge head included in a recording apparatus is configured such that an electric element, such as a capacitor for stabilizing driving of a recording element, is mounted on a member different from a recording element substrate. Japanese Patent Laid-Open No. 2007-268867 discloses an example of such a liquid discharge head. Japanese Patent Laid-Open No. 2007-268867 describes a configuration in which electric components are accommodated in a housing of the head in order to prevent the electric components from being damaged by application of external force. Furthermore, this configuration enables a further reduction in size of the head. However, this configuration, in which the housing accommodates the electric components, has the following disadvantage: insufficient heat resistance of a resin material for the housing may cause the resin material to melt upon excessive heat generation of the electric components.
Excessive heat generation of electric components more often tends to occur due to an increase in power consumption of the electric components resulting from an increase in number of recording elements and an increase in recording density per unit time promoted by recent improvement in recording speed of liquid discharge heads.
The excessive heat generation of electric components may be abnormal heat generation, in which generated heat exceeds an upper limit temperature estimated based on a specification, caused by spontaneous failure or random failure. A resin material for a housing is required to be resistant to abnormal heat generation.
Unfortunately, highly heat-resistant resin materials for such a head housing tend to exhibit low flowability in molding. These materials may be unsuitable for highly advanced molding.
Specifically, low flowability of a material to be molded inhibits molding of a structure with thin walls arranged at high density in a small space. Unfortunately, this restricts the miniaturization of a head housing.
Examples of advanced molding methods include a method of primarily molding a plurality of members in a single die, fitting the primarily molded members to each other in the die, and sealing the interface of the fitted members by secondary molding to join the members. This method is described in, for example, Japanese Patent Laid Open No. 2012-192749.
For such advanced molding, a material having high flowability, or poor heat resistance has to be selected and used in most cases. A disadvantage of such a case is incompatibility between good formability of a head and good heat resistance of a material.